A.9.1 Solver predicates

The following predicates are provided to work with constraints:

{}(+Constraints)

Adds the constraints given by Constraints to the constraint store.

entailed(+Constraint)

Succeeds if Constraint is necessarily true within the current constraint store. This means that adding the negation of the constraint to the store results in failure.

inf(+Expression, -Inf)

Computes the infimum of Expression within the current state of the constraint store and returns that infimum in Inf. This predicate does not change the constraint store.

sup(+Expression, -Sup)

Computes the supremum of Expression within the current state of the constraint store and returns that supremum in Sup. This predicate does not change the constraint store.

minimize(+Expression)

Minimizes Expression within the current constraint store. This is the same as computing the infimum and equating the expression to that infimum.

maximize(+Expression)

Maximizes Expression within the current constraint store. This is the same as computing the supremum and equating the expression to that supremum.

bb_inf(+Ints, +Expression, -Inf, -Vertex, +Eps)

This predicate is offered in CLP(R) only. It computes the infimum of Expression within the current constraint store, with the additional constraint that in that infimum, all variables in Ints have integral values. Vertex will contain the values of Ints in the infimum. Eps denotes how much a value may differ from an integer to be considered an integer. E.g. when Eps = 0.001, then X = 4.999 will be considered as an integer (5 in this case). Eps should be between 0 and 0.5.

bb_inf(+Ints, +Expression, -Inf, -Vertex)

This predicate is offered in CLP(Q) only. It behaves the same as bb_inf/5 but does not use an error margin.

bb_inf(+Ints, +Expression, -Inf)

The same as bb_inf/5 or bb_inf/4 but without returning the values of the integers. In CLP(R), an error margin of 0.001 is used.

dump(+Target, +Newvars, -CodedAnswer)

Returns the constraints on Target in the list CodedAnswer where all variables of Target have been replaced by NewVars. This operation does not change the constraint store. E.g. in

dump([X,Y,Z],[x,y,z],Cons)

Cons will contain the constraints on X, Y and Z, where these variables have been replaced by atoms x, y and z.